1. Field of the Invention
The present invention relates to a lighting system and more particularly, a cold cathode lighting system.
2. Description of the Related Art
Cold cathode lighting is commonly used as an indirect light source that provides a very appealing glow that evenly wash adjacent surfaces & or objects such as walls, ceiling, book cases, furniture, etc. It is used for many different interior and exterior architectural applications. It is used as hidden light source in coves accentuate corner transition between walls and ceilings. In any application it can be used as decorative, supplemental and or functional lighting.
Other light sources that are used in cove lighting systems include in part hot cathode fluorescent lamps, incandescent lamps, PL lamps and LED. The following lists why these lamp configurations have many disadvantages.
Hot cathode fluorescent lamps are only sold in standard straight sizes and not easily made to conform to curves in a cove. They come in limited colors and are not easily made to be dimmable. The lamps cannot be illuminated end to end. They have a relatively short life span.
Incandescent lamps are not energy efficient. Their lifespan is short and need replacement often. A row of bulbs does not produce smooth continuous glow of illumination.
PL lamps also produce uneven illumination. They cannot be dimmed easily and come in only a few colors. They have short life spans.
LED standard output systems for coves have very low light out levels and have a very limited choice of colors.
Cold cathode lighting has many advantages by comparison. Cold cathode lighting has a much longer life span then other light sources. Each lamp illuminates from end to end with no socket interruption and positioned with a small fraction of space between each lamp end resulting continuous shadow free illumination. The lamps can be easily made curved to fit any shape cove and are dimmable. They come in a multitude of colors. There are additional advantages when using low voltage cold cathode lighting systems in that individual fixtures can be produced to achieve the same advantages as mentioned above.
Cold cathode lamps are commonly constructed from 3 tubular glass sections that are fused together. The first tubular glass section is the main body which produces end-to-end illumination. The main body can be produced in almost any specified length that are straight or formed to match the contours of the lamps mounting surfaces such as curved and angular building surfaces. Cold cathode lamps bodies have a maximum length of 8′ and cross sectional diameter ranging from 18 mm to 25 mm. The second tubular glass section is a pair of electrodes, each of which are located on both of the furthermost ends of the lamp body. The third tubular glass section is fused between the electrode and main body as means to extend the distance and orientation of the electrode in relation to the main body as required. Various orientations of the electrodes are required to accommodate the range of configurations including right angles, bend backs, double right angles, etc., that are dictated by different devices including prior art. These devices have been developed to insulate, cover, support, interconnect and/or other related requirements to assist in protecting the electrode from being damaged and/or causing any electrical safety hazards. The electrode is the means for transferring electricity from an external power source through the interior of the lamp between the electrodes to produce the necessary power to excite and illuminate gases such as argon mercury vapor. The construction of each electrode includes leads that are hermetically sealed so that they can extend from the interior of the lamp to its exterior through tip of the electrode. There are various means to safely and securely assist in the continuity between the connection of the electrode leads and electrical wire that originate from the required power source. Depending upon the type of said power source they can be located remotely at varying distances such as 10′, 20′, 30′ or more with the intent that the power sources must still be positioned as close to the cold cathode lamps as possible.
Other types of power sources are located in close proximity of the cold cathode lamps in various types of metal casings that commonly support the main body of the cold cathode lamp mention above. There is an industry standard designation between these two types of power sources used for cold cathode lamps, based on output voltage. The two designations are a) high voltage over 1000 volts such as a high voltage magnetic transformer each of which commonly operate as many as 10 lamps and b) low voltage power source under 1000 volts such as an electronic power supply sometimes referred as a ballast each of which commonly operates one lamp.
Advantages for using low voltage cathode lighting is that it is much safer and therefore complies to the NEC for use in residential applications, whereas high voltage systems are not allowed. Low voltage cathode lighting provides the ability to produce individual fixtures that include one or more casings that support the cold cathode lamp. These fixtures can be prefabricated, eliminating the need to ship separate components to be installed in the field, which is one of the disadvantages for high voltage cold cathode lighting systems. Each low voltage cathode light fixture includes one or more power supply to energize one cathode lamp. There is one cold cathode lamp per fixture. Low voltage cold cathode lighting has a much longer life span then other light sources. The lamps evenly illuminate from end-to-end with no socket interruption. Therefore each lamp can be positioned with a small fraction space between each lamp end, resulting in even, shadow-free illumination. The lamps can be easily curved to fit any cove shape and are dimmable.
There are various devices used to insulate, cover, support, interconnect and/or other related requirements to assist in protecting the cold cathode lamp electrodes from being damaged and/or causing any electrical safety hazards. However what all of these devices have in common is that they all fall short in avoiding damage or breakage of the electrodes as intended. The components of these devices have not been produced to be foolproof from damaging the electrode, tubular extension &/or main lamp body. Such damage can be caused by twisting, applying tension or compression resulting in direct fractures, or tiny hairline cracks, [generally during installation?]. All of which will cause the lamps to become inoperable. The cathode lamp components that have these drawbacks are cold electrode receptacles commonly called lamp holders, polymeric insulator boots, glass insulator cups, double right angle electrode lamp base, amongst others. These drawbacks are described below.
Disadvantages to the right angle orientation are that the lamp is pushed into an electrode receptacle or lamp holder, forcing it until it makes positive contact between the ferrule or button shaped electrode. The lamp can break and cause injury. The lamp also extends out of the lampholder high into the cove requiring a higher cove lip to hide the lamp.
A bend back orientation is where the electrode extension is bent and returns the electrode to the same parallel position as the main glass lamp. A glass cup can be used in place of the polymeric boot, but is large and bulky and requires a clip to keep it from slipping off and is extremely difficult to attach to a mounting surface so that it is positioned correctly.
Glass insulator cups have to manually twist the wire from the power source to the electrode leads and then manually cover that connection with a polymeric boot for insulation with a risk of breakage from the resistance when force is applied.
The disadvantage to a double right angle bend back that uses a bridge support between the main body of lamp and electrode is that physical force has to be applied with the hand to mount it to a contact located at the end of a metal mounting enclosure.